Hitherto, healthcare workers such as nurses have used a light as appropriate when observing states of patients at night.
In the simplest way, a portable light, specifically, a pen light, can be used therefor. For example, there are penlights having a clip or a strap for hanging the light that can be put into a chest pocket without being bulky, and can be taken out to illuminate a patient when required.
In addition, as disclosed in Patent Literature 1, there are also headlight-type lights with which an irradiation direction of the light can be fixed and thus an illumination state of the light can also be controlled through measurement of posture. Therefore, the headlight-type lights are highly convenient.
However, the related art has the following problems. First, there is a problem in that penlights are not always easy to handle because nurses also have medical equipment, a binder, and the like on actual site, and hence both hands are often full.
Headlights are hands-free devices, and hence do not have a problem as that of the penlights. However, headlights including the headlight disclosed in Patent Literature 1 are generally required to have in effect a flat structure with a housing having a short length in order to prevent that a head is shaken or the headlight is hit against other objects. Therefore, there is a problem in that, with the flat structure, light diffuses widely to also fall on eyes of a patient to be observed when his or her oral cavity is to be observed, for example, and hence the patient to be observed is given stress. In particular, on site, there is an opinion from other patients in the shared room that the other patients undesirably awake (are disturbed in their sleep) because the other patients perceive the light during the sleep at night. Accordingly, headlights have a problem in that patients are given stress regardless of whether the patient is the patient to be observed or not.
In addition, in Patent Literature 1, a detection angle is set to 40°, but this angle is too small in actuality when the spread of the light emitted from the headlight is also taken into consideration. That is, the headlight disclosed in Patent Literature 1 has a problem in that the detection angle cannot be considered to be a sufficient angle to prevent the other patients in the shared room from being disturbed in their sleep.